PREFACE. THE following pages contain the substance of the Lectures which, for several years, have been delivered to the classes in Intellectual Philosophy, in Brown University. Having been intended for oral delivery, they were, in many respects, modified by the circumstances of their origin. Hence, illustrations have been introduced more freely than would otherwise have seemed necessary. In preparing them for the press, however, I was led to consider the class of persons for whose use they were principally designed. I remembered the difficulty of fixing definitely in the mind of the pupil the nature and limits of subjective truth; and therefore allowed my instructions to retain in general the form which they had previously assumed. Whether I have in this respect judged wisely, it is not for me to determine. I have not entered upon the discussion of many of the topics which have called into exercise the acumen of the ablest metaphysicians. Intended to serve the purposes of a text-book, it was necessary that the volume should be compressed within a compass adapted to the time usually allotted to the study of this science in the colleges of our country. I have, therefore, attempted to present and illustrate the important truths in intellectual philosophy, rather than the inferences which may be drawn from them, or the doctrines which they may presuppose. These may be pursued to any length, at the option of the teacher. If I have not entered upon these discussions, I hope that I have prepared the way for their more ample and truthful develop ment. It has been my desire to render this work an aid to mental improvement. For this purpose, I have added practical sug gestions on the cultivation of the several faculties. Earnestminded young men frequently err in their attempts at self-improvement. It has seemed to me, therefore, that a work of this kind would be manifestly imperfect, did it not, directly as well as indirectly, aid the student in his efforts to discipline and strengthen his intellectual energies. In order to encourage more extensive reading upon the subject than can be furnished in a text-book, I have added references to a number of works of easy access, specifying the places in which the topics treated of were discussed. In this labor, I have availed myself of the assistance of my former pupils, Mr. SAMUEL BROOKS, now instructor in Greek, in this University, and Mr. LUCIUS W. BANCROFT, of Worcester, Mass. To these gentlemen the student is indebted for whatever benefit he may derive from this feature of the work. For the many imperfections of this volume, the author consoles himself with the reflection, that it has been written and prepared for the press under the pressure of other important and frequently distracting avocations. In the humble hope that it may, nevertheless, facilitate the study of this interest ing department of human knowledge, it is, with diffidence, submitted to the judgment of the public. BROWN UNIVERSITY, Sept. 14, 1854. CONTENTS. SECTION I. — Of our Knowledge of Matter and Mind, SECTION II.-The Perceptive Powers in general, SECTION III. Of our Mode of Intercourse with the External World, SECTION IV. -The Sense of Smell, SECTION V.-The Sense of Taste, SECTION VI.-The Sense of Hearing, SECTION III. — Ideas occasioned by Objects in a State of Rest, SECTION IV.Suggested Ideas occasioned by Objects in the Condi- |